Ginsburg, 85, went home after the fall but continued to experience "discomfort overnight" and went to George Washington University Hospital early Thursday. Tests revealed she fractured three ribs on her left side, and she "was admitted for observation and treatment," according to the court's statement.

Ginsburg, the court's eldest justice, has served for 25 years after being appointed by President Bill Clinton in 1993. She is the leader of the court's liberal wing.

She is a medical warrior, having survived colon cancer in 1999, pancreatic cancer a decade later, a heart stent procedure in 2014 and a previous bout with broken ribs. She works out with a personal trainer twice weekly in the Supreme Court's gym to the beat of the PBS NewsHour.

News of her fall moved swiftly through Washington legal circles Thursday morning, including during and after Kavanaugh's investiture ceremony. Many Ginsburg fans offered support on Twitter.

Known for her work ethic, Ginsburg wrote the first opinion of the Supreme Court’s term this year on age discrimination. The action marked the third consecutive year in which Ginsburg has written the first opinion of the term. Chief Justice John Roberts has remarked about Ginsburg’s speedy delivery of opinions.

"I'm now 85," Ginsburg said in July, according to CNN. "My senior colleague, Justice John Paul Stevens, he stepped down when he was 90, so I think I have about at least five more years."

Given her age, some Democrats have expressed concerns about Ginsburg's health. President Trump has appointed two Supreme Court justices since taking office, and another opening on the bench could ensure conservative control of the court for decades. The Senate, which confirms justices, remains in Republican control after Tuesday's election.

"I pray for Ruth Bader Ginsburg every day," Sen. Bob Menendez, D-N.J., said Sunday. "We cannot allow one more Supreme Court justice to be nominated and get through the Senate by this president, or we’ll lose that court for over a generation."

The second woman appointed to the court – Justice Sandra Day O'Connor became the first in 1981 – Ginsburg is a legend among women's right advocates. She expressed support for the #MeToo movement.

In recent years, she gained celebrity status among liberals – who lovingly refer to her as the "Notorious RBG" – and was the subject a recent documentary, "RBG." Her biography is the subject of an upcoming feature film, "On the Basis of Sex," in which she is played by actress Felicity Jones.

U.S. Supreme Court Justice Ruth Bader Ginsburg talks about her tote bag, at the annual Utah State Bar convention in Sun Valley, Idaho, July 28, 2017. Ginsburg spoke about the evolution of the women's rights movement, what it's like to be interrupted on the bench and life as a pop culture icon during a presentation to a group of lawyers and judges. RICK EGAN, AP

U.S. Supreme Court Justice Ruth Bader Ginsburg acknowledges the crowd's applause before participating in a conversation with Judge Ann Claire Williams of the U.S. Court of Appeals for the Seventh Circuit at Roosevelt University in Chicago, Sept. 11, 2017. CHARLES REX ARBOGAST, AP

Members of the Supreme Court sit for their official photo on Sept. 29, 2009, in the East Conference Room of the Supreme Court. Front row, left to right: Justices Anthony Kennedy, John Paul Stevens, Chief Justice John Roberts, Justices Antonin Scalia and Clarence Thomas. Back row, left to right: Justices Samuel Alito, Ruth Bader Ginsburg, Stephen Breyer and Sonia Sotomayor. Jack Gruber, USA TODAY

Justice Ginsburg, the first Jewish woman to be appointed to the Supreme Court, talks with filmmaker David Grubin as he films his PBS series "The Jewish Americans" on Jan. 10, 2008, in Washington. Kevin Wolf, AP

Justice Ginsburg is bundled up against the cold as she stands with other members of the Supreme Court before the start of the swearing-in ceremony for President-elect George W. Bush at the Capitol on Jan. 20, 2001. Tim Clary, AFP

Justice Ginsburg, left, and Justice Antonin Scalia, center, pose with members of the cast of the opera "Ariadne auf Naxos" following a performance on Jan. 8, 1994, in Washington. The justices, both opera buffs, appeared as extras during the performance. Stephen R. Brown, AP